Figure 1-3. Section of a tooth and jaw.
b. Jaws. There are two jaws, the upper and the lower. The upper is called the
maxilla. The lower is called the mandible.
(1) In each jaw, there are sockets for the teeth. These sockets are known
as alveoli. The bony parts of the jaws holding the teeth are known as alveolar ridges.
(2) The upper jaw is fixed to the base of the cranium. The lower jaw is
movable. There is a special articulation, (T-MJ, temporo-mandibular joint), with muscles
to bring the upper and lower teeth together to perform their functions.
c. Palate. The palate serves as the roof of the mouth and the floor of the nasal
chamber above. Since the anterior two-thirds is bony, it is called the hard palate. The
posterior one-third is musculo-membranous, and is called the soft palate. The soft
palate serves as a trap door to close off the upper respiratory passageway during
d. Lips and Cheeks. The oral cavity is closed by a fleshy structure around the
opening. Forming the opening are the lips. On the sides are the cheeks.